my sweetheart and i are going to pusan from aug 13-15. we want to hit beaches, museums, mountains, historical sites, whatever. we have a lonely planet but i'm used to getting quicker, more well-researched and up-to-date answers from this board.

Alright then everyones going to give you the usual old tosh so ill give you something interesting to do.

Go for a hike between Haeundae beach and (the far nicer and quieter) Sonjong beach. Get on the path that runs behind the beach and walk East to the end of the beach until you get to the fish restaurants...make your way through them and walk up the embankment until you get to the railway line...then follow the tracks round to Sonjong....it will take you an hour.
Its totally safe and nobody will bother you.....youll probably meet a few old locals along the way doing the same thing....There is a small tunnel when you just start off....walk around that ratherthan through it obviously....the trains are few and far between and you hear them coming from miles away.

On a sunny day the views are fantastic...and its all on the flat....You can get a bus from Sonjong back into Busan.